Book Image

Hands-On Machine Learning with scikit-learn and Scientific Python Toolkits

By : Tarek Amr
Book Image

Hands-On Machine Learning with scikit-learn and Scientific Python Toolkits

By: Tarek Amr

Overview of this book

Machine learning is applied everywhere, from business to research and academia, while scikit-learn is a versatile library that is popular among machine learning practitioners. This book serves as a practical guide for anyone looking to provide hands-on machine learning solutions with scikit-learn and Python toolkits. The book begins with an explanation of machine learning concepts and fundamentals, and strikes a balance between theoretical concepts and their applications. Each chapter covers a different set of algorithms, and shows you how to use them to solve real-life problems. You’ll also learn about various key supervised and unsupervised machine learning algorithms using practical examples. Whether it is an instance-based learning algorithm, Bayesian estimation, a deep neural network, a tree-based ensemble, or a recommendation system, you’ll gain a thorough understanding of its theory and learn when to apply it. As you advance, you’ll learn how to deal with unlabeled data and when to use different clustering and anomaly detection algorithms. By the end of this machine learning book, you’ll have learned how to take a data-driven approach to provide end-to-end machine learning solutions. You’ll also have discovered how to formulate the problem at hand, prepare required data, and evaluate and deploy models in production.
Table of Contents (18 chapters)
1
Section 1: Supervised Learning
8
Section 2: Advanced Supervised Learning
13
Section 3: Unsupervised Learning and More

K-means clustering

"We all know we are unique individuals, but we tend to see others as representatives of groups."
- Deborah Tannen

In the previous section, we discussed the constraint we put on our objective function by specifying the number of clusters we need. This is what the K stands for: the number of clusters. We also discussed the cluster's centroid, hence the word means. The algorithm works as follows:

  1. It starts by picking K random points and setting them as the cluster centroids.
  2. Then, it assigns each data point to the nearest centroid to it to form K clusters.
  3. Then, it calculates a new centroid for the newly formed clusters.
  4. Since the centroids have been updated, we need to go back to step 2 to reassign the samples to their new clusters based on the updated centroids. However, if the centroids didn't move much, we know that the algorithm has converged, and we stop.
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